In certain surgical operations it is necessary to cut out and remove fibrous tissue with a high degree of accuracy and from locations which are frequently inaccessible. An example of such an operation is the removal of brain tumors where the tumor needs to be cut out and removed with the minimum possible damage to the surrounding tissue.
There is available on the market a surgical device intended for use in such situations which comprises a first outer tube which is closed at its free end and has an aperture in its side wall a short distance in from the free end of the tube. A second tube is disposed within the first tube and arranged to reciprocate longitudinally along the first tube past the aperture. In this arrangement when the aperture is pressed against an area of tissue some of the tissue will bulge into the interior of the first tube and be severed by the reciprocating second tube. Substantial disadvantages with this arrangement are that, firstly, the tip of the instrument must be pushed past the tissue to be removed to bring the aperture into juxtaposition with the tissue to be removed and, secondly, it is difficult to accurately direct the cutting operation when moving the instrument laterally of its longitudinal axis as is necessary to continue to offer up the aperture to the tissue to be removed.